Invasive Species
Invasive Plant Species
| Species | Native Region | Habitat / Spread | Major Impacts | Special UPSC Notes |
|---|---|---|---|---|
| Acacia (Wattles) | Africa, Australasia | Dry regions; deep roots | Suppresses native flora; destroys grasslands | Conversion of shola–grassland ecosystems in Western Ghats → Nilgiri Tahr habitat loss |
| Billygoat Weed | Tropical America (Brazil) | Rice fields, disturbed land | Crop weed; competes with crops | Medicinal + insecticidal but invasive outside native range |
| Carrot Grass / Congress Grass (Parthenium) | American tropics | Roadsides, farmlands | Allelopathy; severe crop loss | Famine weed; causes dermatitis & respiratory issues |
| Eucalyptus | Australia | Plantations | High water uptake; fodder scarcity | Medicinal but ecologically harmful monoculture |
| Forked Fanwort (Cabomba) | South America | Slow-moving freshwater | Displaces native aquatic plants | Aquarium trade → invasion |
| Lantana | American tropics | Forests, pastures | Reduces biodiversity; toxic to livestock | One of India’s worst forest invasives |
| Mexican Prickly Poppy | Mexico | Roadsides, floodplains | Replaces native species | Seeds resemble mustard → food adulteration |
| Mikania micrantha | Americas | Humid tropics | Smothers crops & forests | Introduced in tea plantations → now major pest |
| Prosopis juliflora | Americas | Arid & semi-arid | Depletes groundwater; blocks wildlife movement | Introduced in Banni grasslands → ecological disaster + charcoal economy |
| Water Hyacinth | South America | Lakes, ponds | Oxygen depletion; aquatic death | “Terror of Bengal”; thrives in eutrophic waters |
| Conocarpus | Tropical regions | Coastal & urban areas | Not palatable; health issues | Banned by Gujarat & Telangana |
Invasive Mammal, Fish & Amphibian Species
| Species | Native Region | Where Invasive | Impact | UPSC Significance |
|---|---|---|---|---|
| Domestic Cat (Felis catus) | West Asia (domestication) | Global | Predation on native fauna | Listed among 100 worst invasive alien species |
| African Catfish | Africa, Middle East | India | Eats native fish; survives pollution | Banned by India (2000) |
| Gambusia (Mosquitofish) | North America | India & others | Harms native fish & amphibians | Policy contradiction: biocontrol vs invasion |
| Indian Bullfrog | South & SE Asia | Andaman Islands, Maldives | Predates native fauna | Example of intra-national invasive species |